The present invention relates to dispensing of livestock feed, and more particularly, to dispensing feed in a continuous and even manner along a bunk for feeding livestock.
The art of automatically supplying feed for livestock to a feed bunk in a feed lot or the like is generally well developed. It has long been recognized that a relatively long feed bunk must be provided for a herd of livestock in order to allow an orderly feeding operation. In this regard, it is of course the objective of the farmer to prevent livestock fighting for position at feed time and allowing the entire herd to have access to the feed on a relatively even basis. The most widely accepted practice in automatic, mechanized feeding today is to provide a traveling trough extending over the feed bunk with an active conveyor to distribute feed from one end or the other of the trough as the trough travels back and forth along the feed bunk.
As background, one of the first successful prior art arrangements for continuous feeding of-this type is shown in the U.S. Pat. No. 3,366,223, to Haen, issued Jan. 30, 1968 and owned by the assignee of the present invention. The feed trough includes one-way passive dividers that push the feed from the trailing end of the traveling trough as the trough moves along the bunk. The dividers press downwardly and rearwardly in order to push the feed out the trailing end. Especially at the start of the travel at either end, when all the dividers are pushing down and rearwardly on the feed, the friction of the feed against the bottom of the trough is substantial. This requires an excessive amount of force and puts a substantial strain on the frame and other supporting components of the apparatus. Furthermore, the ends of the trough tend to be starved since the full feeding does not occur until the trough has moved several feet as the dividers drop fully down into the pushing position. Finally, the dividers may to some extent block or drag the in-feed flow from the conveyor, thus causing some unevenness of distribution in the feed bunk.
To overcome some of the shortcomings of the previous design, a different approach to moving the feed along the trough has been adopted and has met with more commercial success; Haen et al. U.S. Pat. No. 3,428,027, issued Feb. 18, 1969. In this instance, the trough is provided with an active conveyor having pushers scraping along the bottom to take the place of the passive dividers that were previously used. This improvement provides for some reduction in the friction of the feed along the bottom of the trough, and improves the even distribution of the flow to the feed bunk. However, the problem of pushing the feed along the trough, especially as the trough moves from the mid point to the end of the travel requires substantial power input and more stress loading of the components than desired.
Later attempts to change the feeding operation are characterized in the broad concept of an elongated feeding trough moving along the bunk with a bottom formed of clam shell-type doors. As the trough is positioned at the ends of travel, the clam shell doors are opened together dumping the feed in bulk into the bunk below. This concept has met with some success, as represented by the U.S. Pat. No. 3,217,693, to Loesch et al. issued Nov. 16, 1965 and U.S. Pat. No. 3,718,121, Anderson, issued Feb. 27, 1973.
However, the recognized problem in this type of apparatus is generally focused on the inability of the clam shell doors to close tightly. The feed has a tendency, especially in cold weather, to bridge across the doors. When this happens, the feed is improperly distributed along the bunk since the doors remain open as the trough traverses along its path of movement. The Anderson '121 patent suggests improvements in the door closing mechanism but fails to solve the basic problem. In so far as I am aware the attempts have all fallen short of finding an efficient, relatively low power and relatively low cost option to this prior art. As a consequence, the feeders of the Haen et al. '027 type with an active conveyor moving along a movable trough, represents the bulk of the commercial market in the farmstead industry today and for the past several decades.
Other inventors have recognized the shortcoming of the clam-shell doors of the prior art but have failed to provide efficient solutions. For example, the Kenning U.S. Pat. No. 3,769,937, issued Nov. 6, 1973 suggests eliminating the clam-shell type doors altogether by providing a trough that flips at the end of its travel beneath the in-feed conveyor. Such an approach requires increased height to allow clearance over the livestock's heads for the double height rotating trough, or alternatively substantially increased speed of operation to provide the distribution of the feed from a shallow and narrow trough. Furthermore, extended cam/lever actuators at the end of the support frame tend to provide uncontrolled, and thus inefficient and dangerous operation of the pivoting troughs. Clearly, such attempts fall short and suggest the need for departure from these prior teachings to provide a successful bunk feeder utilizing a traveling hopper.